KY-001 Temperature Sensor Module Circuit Working Explanation

The KY-001 Module uses the DS18B20 digital thermometer sensor to measure temperature in Celsius with a resolution of 9-bit to 12-bit. It features an alarm that allows for setting upper and lower temperature limits. This module uses the 1-Wire bus protocol and works with microcontrollers like Arduino, Raspberry Pi, and ESP32. The KY-001 Module is suitable for monitoring temperature in smart homes and controlling temperature in industrial settings.

KY-001 Temperature Sensor Module Specifications

The quick specifications of the KY-001 temperature sensor module is given below:

• Chipset: DS18B20
• Operating Voltage: DC +3.3V to +5V
• Communication: One-Wire Bus
• Temprature Measurement Range: -55°C to 125°C [-57°F to 257°F]
• Measurement Accuracy Range: ±0.5C (between the range -10°C to 85°C)
• Board Dimensions (L x W x H): 28 X 12 x 10 mm
• PCB Color: Black
• Weight: 2gm

Pinout of KY-001 Temperature Sensor Module

The module has 3 male header pins those are - Pin (-): Ground Pin (Middle): DC +3.3V to +5V Pin (S): Digital Signal

Working Explanation of KY-001 Temperature Sensor Module Circuit

Schematic of the ky-001 temperature sensor module circuit is shown below.

Components are used in the circuit - U₁: DS18B20 TO-92, D₁: Red LED, R₁: 4k7Ω Resistor, and P₁: 3 pin Male header.

The main component of the circuit is the DS18B20 sensor, which can operate with a DC supply voltage of +3.3V to +5V. It can draw power from the data line itself, eliminating the need for an external power supply. This "parasitic power" mode makes the setup easier and is great for low-power uses.

When the temperature changes, the sensor's electrical resistance varies. The sensor converts this change in resistance into a digital signal using a built-in analog-to-digital converter (ADC). It uses the 1-Wire protocol, allowing multiple devices or microcontrollers to communicate over a single data line. Each DS18B20 has a unique 64-bit address, enabling individual device identification on the bus.

The module is very accurate, with a margin of ±0.5°C for temperatures from -55°C to +125°C. It can also measure temperature with a resolution of up to 12 bits, allowing for precise temperature readings in small increments.

KY-001 Module Interfacing with Arduino

Connection diagram of the KY-001 temperature sensor module with an Arduino is shown below.

Connect the power pin (middle) and ground pin (-) of the ky-001 module to +5V and GND on the Arduino, respectively. The module signal pin (s) connect to pin 2 on the Arduino.

Arduino Source Code for KY-001 Module

The following Arduino sketch will use DallasTemperature Library by Miles Burton to communicate serially with the ky-001 module, it'll output the temperature read by the device.

To install the library in your Arduino IDE, follow these steps:

1. Open the Arduino IDE
2. Go to Sketch > Include Library > Manage Libraries
3. In the Library Manager, search for each library by typing "DallasTemperature".
4. Click on the Library, select the latest version, and then click on the "Install" button.
5. Wait for the Library to be installed, then close the Library Manager.
6. You can now use the library in the sketch for the ky-001 module.

// Both Libraries will be imported
#include <OneWire.h>
#include <DallasTemperature.h>
// KY-001 Module signal pin is plugged into pin 2 on the Arduino board
#define KY001_ONE_WIRE_BUS 2 //
// Libraries are configured to communicate with the Module
OneWire oneWire(KY001_ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
void setup(void)
{
  // Initialize serial output
  Serial.begin(9600);
  Serial.println("KY-001 temperature sensor measurement");
  // Sensor is initialized
  sensors.begin();
}
// Start the main program loop
void loop(void)
{ 
  // Send the request command to get temperatures
  sensors.requestTemperatures();
  // Output measured temperature
  Serial.print("Temperature: ");
  // You can have multiple ICs on the same bus, where 0 refers to the first IC on the wire.
  Serial.print(sensors.getTempCByIndex(0));
  // Temperature in Celsius
  Serial.println(" °C");
  // 1s pause until next temperature measurement
  delay(1000);
}